Ontological priority
Ontological priority is a philosophical concept that was first introduced by Aristotle in his influential book Categories, in about 350 BCE. For over two millennia, this concept has influenced the reasonings of many philosophers and has influenced some discussion in ontology and logic.
When something is said to be "ontologically prior" to something else, it is literally to say something exists before something else exists. To use René Descartes' famous phrase, "cogito ergo sum," in a slightly different context than the one he originally intended, Aristotle would have agreed with Descartes' reasoning that a person/thinking thing is ontologically prior to the activity of thinking. So, in this case, a positive formulation would be that a thought requires a thinking thing, i.e., the thinking thing has ontological priority over their thought, whose existence depends on the former to exist. Conversely, the negative formulation is that thoughts cannot exist without a thinking thing.
One thing's ontological priority over another may be chronological, by reciprocally and non-reciprocally implied existence, order, "esteem," or "truth-maker," depending on the formulation used.
Ontological Priority in Aristotle's Categories
An ontological priority is an existential type of relationship, between two or more things, that occurs whenever a thing exists only because another thing exists; moreover, that existential relationship only becomes an ontological priority when at least one thing exists before another thing. Whereas if both things came to exist at the same time or bear no meaningful relationship, then an ontological priority cannot be said to occur.With modal reasoning in mind, two of Aristotle's five ontological-priority formulations have it so that if the prior-existing thing were not to exist, then it would be impossible for the posterior-existing thing to exist. These would be among the strongest forms of reasoning in philosophy and logic, since they carry the same certainty as analytic truths, and the denial of any one of them would result in an impossibility.
A "thing" can be a physical object/particular, idea/universal, or a tone/quality and can share an ontological/existential before-after relationship with any of the aforesaid three types of entities. But according to Aristotle, ideas/universals and tones/properties/qualities cannot exist without a particular/physical object; this means that it is impossible, according to Aristotle, for any universal or quality to be ontological prior to any physical object, which was made clear in his arguments against Melissus, and his mentor, Parmenides, among others, in his first book of Physics, as well as other books throughout his Physics and Metaphysics.
If one suspected that the aforementioned trichotomy bears similarities to the type-token-tone framework of C. S. Peirce, a theorist who was not born until about 2,161 years after Aristotle's time, one would be correct. Aristotle's implicit understanding of this trichotomy is already quite evident by his first book of Physics, for example; he makes references and distinctions between the three abundantly. But these similarities between Peirce's trichotomy and Aristotle's implicit one may or may not coincidental. However, "trichotomy" is not the best description for it, since they are interrelated and, in all cases imaginable, inseparable; for example, the property of being a rational or thinking thing and the idea of bipedalism are inseparable from a particular man. For this reason, "triadic" would be a better term, since the three types of ontological phenomena are not mutually exclusive or an either/or. But triadic is a term that must be used with caution to avoid confusion with other ideas that also go by "triadic."
In Aristotle's terminology, this triadic relationship would have much to do with what he calls substance, essence, and accidental attributes, among other things, and according to Aristotle, universals cannot be prior to substance, and accidental features, such as the quality of whiteness, cannot exist without substance either. Bear in mind that C.S. Peirce was influenced by Aristotle and was well-aware of Aristotle's use of particulars, universals, and qualities.
Aristotle's Five Formulations of Ontological Priorities
There are five ways, Aristotle states, that something is ontologically prior to something else, namely, time, reciprocity/non-reciprocity, order, "esteem," and "truth-maker."The first of Aristotle's five formulations of priority is time ; for when one thinks about "priority," it is usually to do with the timewise sense in terms of "before" and "after" or Aristotle's prior and posterior. An example of a timewise ontological priority would be that of a father and son: Aristotle would say that the father is ontologically prior to the son because the father came to exist temporally before the son.
Reciprocity and non-reciprocity of implied existence are the second of Aristotle's formulations and are among the more difficult/complex of them all; the example Aristotle gives of a reciprocal/non-reciprocal ontological priority is through the example of numbers:
In Aristotle's second-formulation example, the existence of two implies one's existence. But one does not reciprocate the existence of two. Two cannot exist without one because two is two by virtue of being two units of one; whereas, by its own nature, one does not need two to exist because one is one unit, not two. Using the same reasoning between two and three, two would, then, become ontologically prior to three because three units reciprocally imply the existence of two units, but two does not reciprocate three, and so on.
Order is Aristotle's third formulation of the ontological priority and is somewhat more or as complex as the previous one; a better way to understand this is the organization of something, be it science, speech, etc. Aristotle gives the example of grammar, wherein "the elements are prior to the syllables". One can extrapolate from the example that words are, by order, ontologically prior to sentences and sentences to paragraphs, etc. Another of Aristotle's examples is, with speeches, the introduction comes before the exposition or explanation, and one can understand from there that the introduction and exposition are ontologically prior to the conclusion.
It is worth reiterating that formulations two and three are two of Aristotle's strongest formulations, which carry apodictic truth values; by contrast, their denial would result in a contradiction, causing impossibility. An example of formulations two and three are: three cannot fail to imply the existence of two because three is, by its nature, defined by its relationship to the numbers preceding it, and a syllable cannot exist without its elements, even under modal realism. Whereas no such examples are possible in the first formulation and the fourth, just below.
While "esteem" is not Aristotle's name for the fourth formulation, he provides none for it. He suggests that it is "perhaps the least proper" of all other formulations because
has more to do with how someone esteems themselves or persons they love/admire as ontologically prior to other persons. This formulation starkly contrasts the more substantive formulations of the three other ontological priorities described above.
Aristotle describes the fourth formulation of the ontological priority as "what is better and more valued is thought to be prior by nature: ordinary people commonly say of those they specially value and love that they 'have priority' ". Aristotle's mention of "by nature" implies that the second formulation of the ontological priority is being misunderstood by people who esteem others, by placing them prior to others by nature; this is so that this aspect of formulation four does not get confused with formulation two. As understandable as it would be that a mother's love for her child, for example, would have her place him as "prior" to other children who are not her own, either by nature or thought, this form of ontological priority is arbitrary and opinion-driven, and it is the simplest among all the formulations. As we saw with Aristotle's comment of this formulation being perhaps the least proper, it is made clear by him that he regards this form of ontological reasoning with disdain.
"Truth-maker" is the fifth and last of Aristotle's formulations of what ontological priorities are, and, as a comprehension heuristic, one could think of it in terms of Alfred Tarski's "x makes it true that p." Alternatively, one may think of the similarities between this formulation and the correspondence theory of truth. As a word of caution: these ideas are not the same, but they have remarkable parallels. Furthermore, the Tarski truth-maker formula and the correspondence theory of truth roughly represent half of Aristotle's formulation; the other half goes above and beyond the truth-making and extends into ontology and the cause of a thing's existence, which is what makes it an ontological priority in the first place.
Before going further, the fifth formulation, dubbed "truth-maker" for naming convenience, is the most complex of them all and is a variation of the second of Aristotle's formulations. But although its certainty is not as high as the second and third formulations, it is stronger than the fourth formulation and either on par with the first, i.e., priority by time, or slightly weaker in terms of certainty. Whatever problems the correspondence theory of truth and Tarski's formula have, the fifth formulation is likewise affected by their problems.
Aristotle gives the example of his fifth formulation of a man and a proposition about him:
In this example, Aristotle, makes it clear that a physical object referenced by a statement cannot be posterior to it; this is related to Aristotle's belief, against Plato's substantive and independently existing Forms/Ideas, that the only reality universals have is with their instantiations in particulars. For example, suppose the universal of bipedality is instantiated in one thing and that thing is the only man who exists; if that man would be destroyed or lose that accidental feature of his being, then the universal would cease to be, at least, until another the universal is instantiated once more. This example illustrates Aristotle's belief that physical objects are ontologically prior to non-physical objects, as with his example of a man being prior to a statement about him. Thus, the statement "There is a man in this house" is true only if there is a man in the house. But the said statement cannot make it so that a man appears out of nowhere in the house so that the statement makes itself true, which is why Aristotle's fifth formulation treats physical objects and other elements that are decisive of bivalent propositions' truth values as their truth-maker, similar to Tarski's formula that "x makes it true that p": the man makes "there is a man" true. But it is worth noting, once again, Aristotle does not explicitly call them "truth-makers"; he strongly emphasizes that particulars determine the truth and falsity of statements, and not the other way around. An example of "other elements" can be a number in "Eight is a number," which is evidently not a statement about a particular but has a non-physical thing as its truth-maker, and this is an area that Aristotle makes no mention or distinctions of, regarding the difference between particulars from ideas/universals and properties/qualities/tones as truth-makers.
Last, Aristotle explained that this formulation, which was dubbed "truth-maker" for clarity, is an expansion, or is a variation, of the second formulation of reciprocity and non-reciprocity of implied existence ; this is to say that, in Aristotle's man-statement example, "For there being a man reciprocates as to implication of existence with the true statement about it ". But the statement itself is non-reciprocal in that respect; it cannot reciprocally imply the existence of a man on its own. That is, the statement "there is a man" does not necessarily mean a man exists, whereas a man implies the existence of the statement "there is a man." The similarities between the correspondence theory of truth and Aristotle's fifth formula is that both involve "matching" a statement with a truth-maker, a "correspondence, hence the theory's name; however, where the two ideas differ is that Aristotle holds truth-makers to be ontologically prior to statements.
Although formulation four is quite controversial, for the presumption that persons are prior or posterior to each other is determined in part "by nature" is often exemplified in racism, formulation five is quite controversial in philosophy because it leaves open-ended questions with respect to anti-realism or scepticism, depending on whether statements are existentially caused by truth-makers or whether statements are only caused to be true per se, thus, opening up the door as to whether the correspondence between "there is a man" and the physical man was dreamt, imagined, hallucinated, mistaken, etc., hence, the problem of realism-scepticism.